Initial backend repository commit.

Set up project files and add .gitignore to exclude local build/runtime artifacts.

Made-with: Cursor

internal/model/group_announcement.go

@@ -0,0 +1,38 @@
+package model
+
+import (
+	"strconv"
+	"time"
+
+	"carrot_bbs/internal/pkg/utils"
+
+	"gorm.io/gorm"
+)
+
+// GroupAnnouncement 群公告模型
+type GroupAnnouncement struct {
+	ID        string    `gorm:"primaryKey;size:20" json:"id"`
+	GroupID   string    `gorm:"not null;index" json:"group_id"`
+	Content   string    `gorm:"type:text;not null" json:"content"`
+	AuthorID  string    `gorm:"type:varchar(36);not null" json:"author_id"`
+	IsPinned  bool      `gorm:"default:false" json:"is_pinned"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+// BeforeCreate 创建前生成雪花算法ID
+func (ga *GroupAnnouncement) BeforeCreate(tx *gorm.DB) error {
+	if ga.ID == "" {
+		id, err := utils.GetSnowflake().GenerateID()
+		if err != nil {
+			return err
+		}
+		ga.ID = strconv.FormatInt(id, 10)
+	}
+	return nil
+}
+
+// TableName 指定表名
+func (GroupAnnouncement) TableName() string {
+	return "group_announcements"
+}